Search

Objectives: Postoperative pancreatic fistula (POPF) is a major concern after pancreatoduodenectomy (PD). We recently designed a new anastomotic method to reduce the rate of pancreatic fistula: polytetrafluoroethylene suture buttress-reinforced pancreaticojejunostomy (PBRP).Methods: An animal model and a computer simulation were used to measure the maximum stress and tensile strength of the pancreas with and without the suture buttresses. Then, a randomized controlled trial (RCT) was performed to compare the outcome of PD between patients who underwent PBRP vs traditional pancreaticojejunostomy (TP).Results: The maximum load in the animal model was significantly higher with the suture buttresses than without (5.47 ± 1.67 N vs 3.72 ± 1.36 N, p < 0.01), and in the computer simulation, the peak stress was lower with the suture buttresses than without (54.86 vs 486.8 MPa). There were no significant differences between the two groups in the overall frequency of POPF, but the rate of clinically relevant POPF was significantly lower in the PBRP group (2.8 vs 22.8%, p = 0.028). The pancreaticojejunostomy time was significantly longer in the PBRP group (19.57 ± 3.31 vs 17.17 ± 4.83 min, p = 0.018), and the PBRP group showed a shorter drainage tube retention duration (10 vs 12 days, p = 0.006) and postoperative hospital stay (13 d vs 15 d, p = 0.031).Conclusions: PBRP is a feasible and reliable procedure for preventing clinically relevant POPF. Additional multi-institution randomized trials should be conducted to confirm these results. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the drug distribution in arteries treated with DES-BMS stenting strategy and to analyze the influence of proximal DES on distal segments of BMS. A straight artery model ( Straight Model) and a branching artery model ( Branching Model) were constructed in this study. In each model, the DES was implanted at the proximal position and the BMS was implanted distally. Hemodynamic environments, drug delivery and distribution features were simulated and analyzed in each model. The results showed that blood flow would contribute to non-uniform drug distribution in arteries. In the Straight Model the proximal DES would cause drug concentration in BMS segments. While in the Branching Model the DES in the main artery has slight influence on the BMS segments in the branch artery. In conclusion, due to the blood flow washing effect the uniformly released drug from DES would distribute focally and distally. The proximal DES would have greater influence on the distal BMS in straight artery than that in branching artery. This preliminary study would provide good reference for atherosclerosis treatment, especially for some complex cases, like coronary branching stenting. [ABSTRACT FROM AUTHOR]

Helical flow has been introduced to improve the hemodynamic performance of vascular devices such as arterial grafts, stents and arteriovenous shunts to overcome the flow induced thrombus formation and intimal hyperplasia. However, the quite low intensity of helical flow in the existing devices may limit their function. To obtain desirably high intensity, inspired by the helical flow and tapered configuration of the arterial system, we proposed a new conceptual design of the medical devices, which take the form of a tapered helical shape. We demonstrated its effectiveness in arterial grafts by numerically comparing the hemodynamic performance of helical grafts with different smooth tapers. The results show that the helicity density quantifying the helical flow enlarges sharply with the increase of the taper under both steady and pulsatile flow conditions. Moreover, the amplified helical flow induced by the taper would lead to highly elevated wall shear stress, remarkably reduced oscillating shear index and relative residence time at both the grafts and the anastomosis of the host vessel. The present findings therefore indicated that the new helical graft with taper would significantly enhance the helical flow in the grafts and host vessel, which may reduce the possibility of thrombus formation in the graft and intimal hyperplasia in the host vessel and hence improve the graft patency. In addition, the concept of helical shape with taper may also be applied to design arterial stents and arteriovenous shunts to obtain better hemodynamic performance. [ABSTRACT FROM AUTHOR]

Vesicle transport plays important roles in plant tolerance against abiotic stresses. However, the contribution of a vesicle formation related protein CaSec16 (COPII coat assembly protein Sec16-like) in pepper tolerance to salt stress remains unclear. In this study, we report that the expression of CaSec16 was upregulated by salt stress. Compared to the control, the salt tolerance of pepper with CaSec16 -silenced was compromised, which was shown by the corresponding phenotypes and physiological indexes, such as the death of growing point, the aggravated leaf wilting, the higher increment of relative electric leakage (REL), the lower content of total chlorophyll, the higher accumulation of dead cells, H 2 O 2 , malonaldehyde (MDA), and proline (Pro), and the inhibited induction of marker genes for salt-tolerance and vesicle transport. In contrast, the salt tolerance of pepper was enhanced by the transient overexpression of CaSec16. In addition, heterogeneously induced CaSec16 protein did not enhance the salt tolerance of Escherichia coli , an organism lacking the vesicle transport system. By yeast two-hybrid method, an ankyrin protein, CaANK2B, was identified as the interacting protein of CaSec16. The expression of CaANK2B showed a downward trend during the process of salt stress. Compared with the control, pepper plants with transient-overexpression of CaANK2B displayed increased salt tolerance, whereas those with CaANK2B -silenced exhibited reduced salt tolerance. Taken together, both the vesicle formation related protein CaSec16 and its interaction partner CaANK2B can improve the pepper tolerance to salt stress. [ABSTRACT FROM AUTHOR]